S7 steel

T Blade

T Blade

Joined
Aug 25, 2003
Messages
1,466
Hello Fellas,

A machinist friend just gave me about 20 3/8" diameter rods of S7. Is it good for forging? If so, how does it move under the hammer, is it red hard, how is it to weld with other materials, and finally what quenching medium would be used?

Thanks for the information.

IG, I could bring some of it to the hammerin
:D :D :cool:
 
I exchanged a few emails with a smith over on another forum about S7. He said it forged well and that he quenched in oil. I got some a long time ago and have just sent a piece that I did stock removal on out to Roger Linger (rlinger) to heat treat. It is a air hardening steel but appears that it can take a oil quench, according to the one guy. To be honest I could not find alot of people that had worked with it. Good luck and let us know how it works.
 
S7 - forge 1900-2050F, harden - 1700-1750 F ,Air quench. Forging - somewhat subject to decarburization preheat before bringing to forging temp.Since they are air hardening anneal rather than normalize.
 
S7 grinds well. Don't know about forging it. This one was ground on the rotary platen out of 3/16" stock. I heat treated it before grinding, quenched it in the aluminum plates and double tempered it. Rockwell is 60. Tends to rust if you're not careful. I etched it later to bring out the grain but haven't taken a picture yet. Handle is Koa burl wood.
See? I can do something other than gray (grey) turds :)
 
Kit Carson said:
S7 grinds well. Don't know about forging it. This one was ground on the rotary platen out of 3/16" stock. I heat treated it before grinding, quenched it in the aluminum plates and double tempered it. Rockwell is 60. Tends to rust if you're not careful. I etched it later to bring out the grain but haven't taken a picture yet. Handle is Koa burl wood.
See? I can do something other than gray (grey) turds :)
Click to expand...
Beautyyyy. I like the knife Kit. I mean I like the knife you made Kit. ;) ;)
 
Thanks Fellas,

The information/comments that you offered. As these pieces are round bar, I have no choice to forge. Before I do that though, I've at least 7 blades that are forged to shape, but are in serious need of grinding, attachments, etc. :D

Uh Oh... :eek: Started warming up yesterdays coffee in the microwave, and when I turned it on it started crackleing, popping, and... :eek: smelling of burnt wires... :eek:

Just what I need, another bill for replacement/repair.

Kit, the knife is a beauty :)

Again, guys, thanks for the input.

:D :D :cool:

Larry T
Member of NECKA
 
On the S7 Bowie that Mark sent me (above post - Mark Nelson), I first air quenched it but its massive size, 1/4" max thickness - 14 1/4 OAL, was too much for my air flow and it only tested 56 HRc after snap temper. I re-did it quenching in 130 F oil and after snap temper it tests a solid 59 HRc, right on target for about 57 - 57.5 HRc after tempering which should give maximum toughness. I want 58. I'll see but want to temper at 400 F. Because of the small amount of vanadium and some chromium I have it in cryo. I'll post finals here.

The blade is very impressive to me. It is a convex grind with absolutely zero noticable facets and a consistant distal. I enjoy working with good craftsmanship.

RL
 
Kit Carson said:
S7 grinds well. Don't know about forging it. This one was ground on the rotary platen out of 3/16" stock. I heat treated it before grinding, quenched it in the aluminum plates and double tempered it. Rockwell is 60. Tends to rust if you're not careful. I etched it later to bring out the grain but haven't taken a picture yet. Handle is Koa burl wood.
See? I can do something other than gray (grey) turds :)
Click to expand...


Kit , I keep telling folks that you are not just a "one trick pony"
Is this the one you showed me a Trackrock? If so it's a beauty and the surface finish is something to see, especially for us guys that go nuts over grain patterns.
 
I love the knife Mr. Carson. Have you one any cutting withit to get a impression of S7, or do you have any thoughts on it in general. Thank you very much for the kind words Roger. Thank you for the extra effort in the oil quench. That was above what you had to do. There was more time put into that blade then there should have been trying to get the balance were I wanted it with the taper. I learned alot about grinding with that beast. I learned that I have alot more to learn! :p Once more many thanks.
 
No need to be concerned about any extra efforts. They don't leave unless I am satisfied.

RL
 
Mark's S7 Bowie is 57 HRc after double tempering @ 400 F. / 1 hour per. Austenitizing was @ 1725 F for 27 minutes. A slow ramp to pre-heat @ 1350 F / 7 minutes was done before ramping to austen.. Quenching in 130 F oil followed by 1 hour snap temper @ 280 F before falling below hand warm. Even though I deep cryo'd because of the vanadium and chromium carbides, cryo did nothing in increasing hardness (it remained 59 HRc - same as after snap temper).

This should be a VERY tough blade at its 57 HRc.

RL
 
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